Method for sorting mailings according to the distribution sequence

ABSTRACT

Method for sorting mailings according to the distribution sequence in a sorter unit with circulating pouches, the number of pouches in a pouch circuit being less than the number of mailings for sorting in said sorting run. After all pouches are loaded, the separation and reading of the remaining mailings for the sorting run is carried out and the mailings are divided into one part for corresponding mailing points for the beginning or end of the sequence, and another part for all the charged mailings, which are then buffered. The mailings in the pouches are then sorted according to the sequence. The buffered mailings are placed in the empty pouches and then separated into further distribution sections, when not all buffered mailings fit in the pouches. Once all pouches are filled with the buffered mailings for the subsequent distribution section the next sorting is carried out.

BACKGROUND OF THE INVENTION

The invention relates to a method for sorting mailings according to adistribution sequence.

The task of sending out mailings is made considerably easier if thesequence of the volumes of mailings for the individual mailing points inthe mailing containers corresponds to the sequence of mailing points onthe mailing path.

A number of devices for the production of such distribution sequencesthat take special account of large letters are known, some of which relyon single pass methods.

Such a method is characterized by the fact that the whole mailing volumethat is to be brought into a distribution sequence is separated onlyonce, as described, for example, in EP 0 820 818 A1 and DE 199 43 362A1.

Multi-pass methods on the other hand are characterized by multipleseparations of the whole mailing volume, as described, for example, inEP 1 258 297 A1.

Another known method involves carrying out a pre-sorting and a finalsorting on a sorting machine at the same time if the capacity requiredfor the final sorting is greater than the capacity that is available inthe sorting machine for the final sorting. Thus some of the mailings arealready finally sorted in the first sorting run. The remaining mailings,that were initially only pre-sorted, are again sent to the sortingmachine for final sorting. In this method the pre-sorting follows apre-sorting plan that has been fixed before pre-sorting, as described,for example, in EP 0 999 902 B1.

Distribution sequence sorting machines comprising a single pass processare known exclusively in the pouch sorter design, wherein the ring ofpouches functions as a storage unit having optional access to thestorage points thereof. This fundamentally limits the mailing volume asa function of the number of pouches in the sorter, which has to be equalto or greater than the mailing volume. Hitherto no methods for pouchsorters have been disclosed that allow a precise division of the mailingvolume to be processed into corresponding partial volumes without priorinformation about the mailings. These partial volumes are in each casecharacterized by having a coherent range of mailing points and aresmaller than or equal to the capacity of the machine (that is the numberof pouches in the ring of pouches).

SUMMARY OF THE INVENTION

The object of the invention is to provide a generic method for sortingthe mailings according to the distribution sequence in a sorter havingcirculating pouches each for one respective mailing, the number ofpouches in a ring of pouches being less than the number of mailings forsorting, and in which method the number of reading and divisionprocedures is reduced.

Accordingly, one aspect involves a method for sorting mailings accordingto a distribution sequence in a sorter having circulating pouches,wherein a number of pouches in a ring of pouches is lower than a numberof mailings that are to be sorted. The mailings are separated, theirmailing addresses are read, and loaded into the pouches until each pouchis filled with one mailing. Remaining mailings are separated, and theirmailing addresses are read. The mailings are divided into a firstportion for coherent mailing points at a beginning or at an end of thedistribution sequence, and into a second portion for ejected mailingsthat do not fit into the pouches. The first portion is in the pouches atthe end of said dividing, and the mailings of the second portion arebuffered. The dividing is achieved by exchanging the mailings in thepouches and ejecting the mailings that have been exchanged or by directejection through at least one separation outlet of the sorter. Themailings located in the pouches are sorted according to the distributionsequence. The buffered mailings are fed, and separated and loaded intoempty pouches, and divided into distribution sections of thedistribution sequence if not all the buffered mailings fit into thepouches. When all the pouches are filled with the buffered mailings foran adjacent distribution section, the buffered mailings are sortedaccording to the distribution sequence of the adjacent distributionsection. At least one of the dividing and sorting process is repeatedwith the separated mailings until all the mailings are sorted.

In the method according to the invention, the sorter does not first runempty in the first sorting run before the following sorting run canstart. As a result of the fact that in the first sorting run, in whichall the mailings are read and separated, the mailings remaining in thepouches are first separated and subsequently arranged in sequence, it isnow only the separated mailings that still require further processing.

Thus in order to reduce the amount of reading and the number of readingerrors, it is advantageous, after the first division, to provide themailings with machine-readable identification symbols, store the mailingaddresses that have been read in a data file according to theidentification symbols, and when mailings are input again to read onlythe identification symbols and identify the mailing addresses with theaid of the data file.

For simple and safe division it is advantageous, in the first sortingaccording to the coherent mailing points at the beginning of adistribution sequence, to exchange the mailing in the pouches with thehighest position in the distribution sequence for the next mailing thathas been input and eject it via a separation outlet, if the position ofthe mailing in this pouch in the distribution sequence is higher thanthat of the newly input mailing, or in the first sorting according tothe coherent mailing points at the end of a distribution sequence, toexchange the mailing in the pouches with the lowest position in thedistribution sequence for the next mailing that has been input and ejectit via a separation outlet, if the position of the mailing in this pouchin the distribution sequence is lower than that of the newly inputmailing. The above procedure is repeated until all the mailings have runthrough the sorter.

If there is prior knowledge available relating to the mailing addressesof the mailings to be sorted, for example from readings of previouslystored processes, then the mailings that are to be separated areadvantageously subdivided over a plurality of division processes intosections of the distribution sequence and ejected. As a result of theabove pre-sorting of the separated mailings, a considerable reduction indivision and separation work can be achieved in the case of largermailing volumes.

In order to reduce sorting times it is advantageous to carry out thesorting by emptying the pouches and loading empty pouches with separatedor new mailings at the same time.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The novel features and method steps characteristic of the invention areset out in the claims below. The invention itself, however, as well asother inventive features and advantages thereof, are best understood byreference to the detailed description, which follows, when read inconjunction with the accompanying drawings, wherein:

FIG. 1 depicts a flow chart showing the stages of the sorting process,and

FIGS. 2 a-g depict a simplified illustration of the division process indiagram form.

DETAILED DESCRIPTION OF THE INVENTION

The method shown in FIG. 1 is as follows:

The first step is: separation, reading of the mailings and filling ofall the circulating pouches 1, from which the mailings can be placedinto a predetermined order by means of carefully targeted opening of thepouches.

Then follows the separation and reading of the remaining mailings inthis sorting run and the division of the mailings from the beginning orend of the distribution sequence which fit into the pouches and are inthe pouches at the end of the distribution sequence from the remainingmailings that are ejected and buffered 2. The mailings in the pouchesare then sorted in a known manner into the predetermined distributionsequence according to the mailing addresses that have been found forthem (sequencing) 3.

Subsequently, or even during the sequencing, as soon as the pouches areempty, there follows the separation and reading of the mailings andfilling of the empty pouches until all the pouches have been filled withthe buffered mailings 4.

Once all the buffered mailings are in the pouches, they are then sortedaccording to the distribution sequence 5 and the whole sorting processis complete. If, however, the number of buffered mailings is greaterthan the number of pouches in the circulating ring of pouches, therethen follows the separating and reading of the further mailings and thedivision of the mailings from an adjacent section in the distributionsequence that are in the pouches at the end of said division process,together with the ejection and buffering of the mailings that now remain2. Once this process has been completed, the mailings in the pouches inthe distribution sequence of this section are sorted 3. Then thecurrently buffered mailings are separated, read and transported into theempty pouches until all the pouches have been filled 4.

If all the buffered mailings are now in the pouches 5, the sequencing ofthe last mailings for the respective section then ensues and the sortingrun is complete, and if they are not, then another division/sequencingensues as described above. The process of division is explained with theaid of FIGS. 2 a-g using a simple example in diagram form. The sorterfor said embodiment has a circulating ring of pouches, the pouches ofwhich are emptied onto a subdivided conveyor belt in such a way that themailings at the end of the subdivided conveyor belt are transported inthe distribution sequence into a container or combined.

The numbers on the ten mailings that are to be sorted show the sequencein the mailing operation, i.e. mailing 1 is mailed first and mailing 10last. The ring of pouches has 5 pouches, each of which takes onemailing, and which empty their content in a controlled manner onto thesections of the subdivided conveyor belt or separately (FIG. 2 a).

First, the first 5 mailings in the pile, with the numbers 1, 3, 8, 9, 6are loaded into the 5 pouches (FIG. 2 b). Since the number of mailingsexceeds the number of pouches, and at the start, the mailings to besequenced are those at the beginning of the distribution sequence, themailings at the end with the numbers 6 to 10 are first ejected. This isachieved by the remaining five mailings being likewise fed into thesorter, separated and read. Since the first portion of the mailings forthe distribution route is to be sequenced first, the mailings in thepart at the rear have to be separated. This is achieved by the mailingin the pouches having the highest value in the distribution sequencebeing exchanged for the mailing which has just been separated that has alower order of precedence in the distribution sequence and beingejected.

If, on the other hand, the new mailing has an even higher value, it isejected immediately. This means that first mailing 2 is exchanged in thepouch for mailing 9, by mailing 9 being ejected and mailing 2 beingloaded into the pouch that has been vacated (FIG. 2 c). Then the nextmailing 7 is exchanged for mailing 8 (FIG. 2 d).

Since the mailing 10 that is subsequently fed in is higher in the orderof precedence than all the other mailings that are in the pouches, it isejected immediately (FIG. 2 e). Finally, mailing 4 is exchanged formailing 7 and mailing 5 is exchanged for mailing 6 (FIGS. 2 f and 2 g).

The mailings that have been ejected 10, 6, 9, 7, 8 are buffered andmailings 5, 2, 4, 3, 1, which are in the pouches, are emptied onto theconveyor belt in the correct order of precedence and from there stackedinto a container. Subsequently the separated and buffered mailings 10,6, 9, 7, 8 are once again fed into the sorter and immediately sequencedsince the number thereof coincides with the number of pouches, and aretransported into the container. Therefore, the container now containsthe ten mailings in the distribution sequence. If the number of mailingshad still been greater than the number of pouches, then a furtherdivision process would have had to be carried out.

1. A method for sorting mailings according to a distribution sequence ina sorter having circulating pouches, wherein a predetermined number ofpouches is lower than a number of mailings to be sorted, and wherein thedistribution sequence includes coherent mailing points in apredetermined order of distribution, wherein the order of distributionbegins at a first distribution point and ends at a last distributionpoint, the method comprising: in a first phase, separating a mailingfrom the number of mailings to be sorted; reading a mailing address ofthe mailing; determining a distribution point assigned to the mailingaddress and determining a position of the distribution point within theorder of distribution; loading the mailing into an empty pouch;repeating the steps of the first phase until each pouch is filled withone mailing; in a second phase, if all pouches are filled, separating asubsequent mailing from the number of mailings to be sorted; reading amailing address of the subsequent mailing; determining a distributionpoint assigned to the mailing address of the subsequent mailing anddetermining a position of the distribution point within the order ofdistribution; if the position of the distribution point assigned to themailing address of the subsequent mailing is lower than a highestposition of a distribution point of a mailing in a pouch, feeding themailing having the highest position from the pouch to a buffer, andloading the subsequent mailing into the pouch; if the position of thedistribution point assigned to the mailing address of the subsequentmailing is higher than the highest position, feeding the subsequentmailing to the buffer; and repeating the steps of the second phase untilthe pouches include only mailings having neighboring distributionpoints.
 2. The method of claim 1, further comprising extracting themailings from the pouches according to the order of distribution.
 3. Themethod of claim 2, wherein the extracted mailings include a mailingassigned to the first distribution point.
 4. The method of claim 1,further comprising providing the mailings with machine-readableidentification symbols once the mailings are separated for the firsttime, and storing the mailing addresses in a data file in associationwith the identification symbols, so that when the mailings are fed inonce again only the identification symbols are now read and the mailingaddresses are determined via the data file.
 5. The method of claim 1,further comprising repeating the first and second phases until allmailings are sorted.